Hub installing retaining and withdrawing device and method

ABSTRACT

A device and method for the purpose of installing, retaining, and withdrawing a large hub on a shaft such as in ship&#39;&#39;s propeller mountings. The device comprises a backing plate which is secured to the end of a shaft by means of bolts. A hydraulic jack including an annular piston is mounted in the face of the backing plate to assist in pushing the hub on the shaft. When the hub is in place on the shaft, the bolts are tightened and sealant is injected into a sealant recess between the backing plate and the face of the tailshaft. For withdrawal of the hub, the bolts are removed from engagement with the shaft and are located on an outer flange of the backing plate to secure the backing plate to the hub. A second hydraulic jack, mounted in a recess of the backing plate adjacent the end of the shaft, is used to urge the hub backing plate assembly aftward of the tailshaft taper.

United States Patent Herbage 1 Oct. 17,1972

HUB INSTALLING RETAINING AND WITHDRAWING DEVICE AND METHOD 72 Inventor: Bernard s. Herbage, 7520 Horn wood, Apt. 904, Houston, Tex. 77036 [22] Filed: March 9, 1970 [21] Appl. No.: 17,523

[52] US. Cl ..416/146, 416/244 [51] Int. Cl. ..B63h 1/20 [58] Field of Search ..416/244, 174, 146, 204

[56] References Cited UNITED STATES PATENTS 3,469,556 9/1969 Campbell et a1 ..416/244 X 3,549,275 12/1970 Laskey... ..416/244X 3,061,342 10/1962 Feller"; ..416/244 3,228,482 1/1966 Bunyan ..416/244 3,358,772 12/1967 Bunyan ..416/204 Primary Examiner-Everette A. Powell, Jr. Attorney-Arnold, White and Durkee [5 7] ABSTRACT A device and method for the purpose of installing, retaining, and withdrawing a large hub on a shaft such as in ships propeller mountings. The device comprises a backing plate which is secured to the end of a shaft by means of bolts. A hydraulic jack including an annular piston is mounted in the face of the backing plate to assist in pushing the hub on the shaft. When the hub is in place on the shaft, the bolts are tightened and sealant is injected into a sealant recess between the backing plate and theface of the tailshaft. For

' withdrawal of the hub, the bolts are removed from engagement with the shaft and are located on an outer flange of the backing plate to secure the backing plate to the hub. A second hydraulic jack, mounted in a recess of the backing plate adjacent the end of the shaft, is used to urge the hub backing plate assembly aftward of the tailshaft taper.

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FIG.8

Bernard 5. Herbage INVENTOR ATTORNEYS HUB INSTALLING RETAINING AND WITHDRAWING DEVICE AND METHOD BACKGROUND OF THE INVENTION This invention relates to an improved method and device for installing, retaining and withdrawing a hub of large size on a shaft. The invention has particular application to ships propellers and will be so described in the following.

A state-of-the-art device for installing, retaining and removing a ships propeller is described in US. Pat. No. 3,358,772. This device, which is designed for use with threaded tail shafts, includes a large diameter nut which is screwed onto a tail shaft to push the hub of the ship's propeller into place along the tail shaft taper. The nut includes an annular recess on the side adjacent the hub. Within this recess is a hydraulic jack mechanism which includes a piston. When hydraulic fluid is injected into the jack, the piston ring urges the hub of the propeller into place on the shaft. For removal of a propeller hub the securing nut is reversed and screwed back into place. Then there is secured at the rear of the tail shaft a backing plate which is secured by bolts to the propeller hub. Fluid pressure is then injected into the hydraulic jack and the propeller hub is withdrawn from the tail shaft.

SUMMARY OF THE INVENTION The present invention provides an improvement over the state-of-the-art device described above. This invention includes a hydraulic mechanism for installation of the propeller hub and also a separate hydraulic mechanism for withdrawal. Hence, by the present invention, reversal of the retaining device is not required to effect removal of a propeller hub.

In addition, the present invention has the following advantages and features, among others:

(I) A threaded tail shaft is not required so that the present invention can be used for installing and retaining propeller hubs on damaged shafts which must be remilled without the threaded tail portion.

(2) An integral unit is provided so that no withdrawal plates, bolts or supplementary equipment need be maintained on board for withdrawal of a propeller hub. Certain prior art devices have required a separate plate or set of bolts which were difficult to stock or locate on board the vessel. Often, these extra parts became lost so that the necessary equipment was not available on board the vessel for withdrawal of a propeller during reworking or maintenance operations.

(3) Means is provided by the present invention to minimize damage due to lateral shearing forces which might strike the propeller or hub. A projection extends beyond the tail shaft into a recess within the retaining device.

BRIEF DESCRIPTION OF THE DRAWINGS The invention is illustrated by way of example in the accompanying drawings in which:

FIG. 1 is a schematic diagram, partly in section, of the propulsion area of a vessel;

FIG. 2 is an elevation, partly in section, of an embodiment of the invention as installed to retain propeller hub on a tail shaft;

FIG. 3 is an elevation, partly in section, of an embodiment of the invention illustrating the. equipment for withdrawal of a propeller hub;

FIG. 4 is an elevation, partly in section, of a modification of the invention which provides an integral flange for withdrawal and requires no separate withdrawal ring;

FIG. 5 is an elevation, partly in section, of another modification of the invention providing for an integral clamping for a fair water cap and the withdrawal plate;

FIG. 6 is an elevation, partly in section, of still another modification of the invention where a large, hydraulic pressure head is provided'for withdrawal, particularly with hollow tail shafts.

FIG. 7 is an elevation, partly in section, of still another modification, of the invention using a pull up guide stud and shows the retaining device separated from the tail shaft during installation; and

FIG. 8 is an elevation, partly in section, of the device of FIG. 7 as installed on the tail shaft with the guide stud removed.

DETAILED DESCRIPTION OF THE DRAWING FIG. 1 General Description Referring now to FIG. 1, there is shown the stern portion of a vessel 10 including a rudder l2 and a propeller 14. The assembly around the tail shaft is shown in cutaway at 16. The propeller 14 is mounted over the tail shaft 16 by a bar on hub 14a. The device of the present invention, indicated generally at 18, retains the hub 14a in place on the tail shaft 16 as well as aids in installation and withdrawal of the hub 14a. A fair water cap 20 is shown positioned over the aft end of the tail shaft 16.

Many propellers such as shownat 14 are of large diameter in the order of 20 or 30 feet and weigh 20 tons or more. The installation of such a propeller can present a large, technical problem, particularly in harbors and ports where a ship could find itself without sufficient men and equipment to perform the task.

FIG. 2 Installation Procedure Referring now to FIG. 2, there is shown the improved form of device 18 in accordance with the present invention. In enlarged form compared toFlG. l, the hub 14a is shown in position around the tail shaft 16. The

drawing of FIG. 2 is shown with the propeller and hub in position on the tail shaft but without the fair water cap being placed in position over the aft end.

The procedure for installing the hub 14a on shaft 16 will be described later, but first the basic elements of the assembly will be described in detail. The assembly includes a backing plate 22 which encloses the aft end of the tail shaft 16, abuts the surface of the hub 14a, and aids in retaining it in position.

The backing plate 22 is held in position by means of a plurality of bolts, two of which are shown at 24 and 26. Bolts 24 and 26 extend through bores in backing plate 22 and are received in threaded openings 24a and 26a, respectively, in the tail shaft 16.

In accordance with the present invention, the tail shaft 16 includes a projection 16a which has a smaller diameter than the main tapered portion of the tail shaft. Projection 16a fits within a recess inside the inner surface of the backing plate 22. The combination of the recessed portion of the retaining ring 22 and the pro- 3 jection 22a provide the nonshearing feature mentioned above, in that the propeller retaining assembly will be able to withstand lateral impacts perpendicular to the axis of the tail shaft 16.

Included within an annular recess of the backing plate 22 is an annular piston 28. Between the inner end of the annular recess and the face of the piston 28 is an expandable ring 30. Injection of fluid under pressure into expandable ring 30 results in exertion of outward force from the piston ring 28. As piston ring 28 contacts the hub 14a it aids in urging the hub onward of the shaft 16. Fluid pressure is injected into the expandable ring 30 by means of a tube 32 which extends through a passageway in backing plate 22, extending from the inside of ring 30 to the rear portion of backing ring 22.-A gasket or sleeve 34 is located in the passageway between the tube 32 and the wall of the retaining plate 22. The expandable ring 30 may be constructed of any suitable elastomer material such as rubber or neoprene. The injection tube 32 includes a fitting at its outer end which can be readily coupled to a hydraulic device or gun for inserting fluid pressure into the expandable ring 30.

By a further feature of the present invention, a novel sealing mechanism is provided which comprises an annular recess 40 into which is injected a sealing material or sealant such as red lead. The sealant is injected through a passageway 42 which extends from the annular recess 40 through the backing plate 22 to the exterior and includes a threaded portion 42a for receiving the fitting of a gun or device for injecting the sealant. Another passageway 41 acts to vent the annular recess 40.

Once the backing plate 22 is in place over the end of the hub 14a and the bolts 24 and 26 are locked in place securely, sealant is injected through the passageway 42 into the annular recess 40. An O-ring 43 mounted in an annular recess in the face of backing plate 22 provides a seal to prevent the escape of the sealant within the annular recess 40. 7

As a further improved feature of the present invention, novel means are provided for aiding in the withdrawal of the hub 14a without requiring any reversal of the backing plate 22. The withdrawal means in- .clude an expandable bladder 44 shown in the shape of an oblate spheroid. Bladder 44 is mounted within a space between the aft end of the projection 16a of the shaft 16 and the inner wall 22a of the retaining plate 22.

An injection tube 46 extends through a passageway in backing plate 22 from the interior of the expandable bladder 44 to the outside of the backing plate 22. An insulating sleeve or seal 48 is mounted in an annular manner within the passageway in which rests the injection tube 46. Fluid pressure can be injected within the expandable bladder 44 by means of an external hydraulic gun which is fitted to the injection tube 46. Fluid pressure injected within the bladder 44 causes outward expansion which pushes outwardly on the tail shaft 16 and thus aids in withdrawing the entire assembly, including hub 14a and backing plate 22 (when the bolts 24 and 26 are removed and replaced as described below).

The expandable bladder 44 may be constructed of a tough, durable material such as rubber, which is capable of withstanding high pressure on the order of 10,000 pounds per square inch. An O-ring S0 is provided at the outer edge of the projection 16a to prevent extrusion of the bladder 44 into the interface at 16b between the tail shaft 16 and the backing plate 22.

Installation Procedure Referring again to FIG. 2, there will be described briefly the steps involved in installing the hub 14a on the tail shaft 16. I (I) By use of the conventional hoisting and supporting mechanism the hub 14a is placed loosely over the end of the tail shaft 16. The backing plate 22 then is placed over the aft end and the bolts 24 and 26 are screwed into threaded openings 24a and 26a respectively.

(2) The bolts 24 and 26 are tightened until the backing plate 22 is pressed tightly against the aft end of the hub 14a.

(3) Fluid pressure is injected by means of a hydraulic gun through the injection tube 32 into the expandable ring 30. Hence, the piston 28 is forced outwardly to urge the hub 14a further onward of the taper of tail shaft 16.

(4) The bolts 24 and 26 are again tightened and again fluid pressure is injected into the expandable ring 30 to force the piston 28 further outward and urge the hub 14a further onward of the tail shaft 16.

(5) The foregoing steps continue until the hub 14a is mounted securely in the correct position around the tail shaft 16 and the bolts 24 and 26 are tightened to a predetermined torque.

(6) Sealant is then injected by means of an external device through the passageway 42 into the annular recess 40.

FIG. 3 Withdrawal Procedure Referring now to FIG. 3, there will be described further construction of the improved device in accordance with the present invention and particularly the construction for withdrawal of the hub 14a.

The assembly for aiding in withdrawal of the hub 14a is illustrated in the form of a withdrawal ring 51 which includes a shoulder 51a that rests on a flange 22b. The withdrawal ring 51 is secured in place by a plurality of bolts, two of which are illustrated at 52 and 54, which are received in threaded openings 52a and 54b in the hub 14a.

In withdrawal of the hub 14a, the bolts 24 and 26 are removed from the positions shown in FIG. 2 and are placed in the positions at 52 and 54 shown in FIG. 3. Fluid pressure is then injected into the expandable bladder 44 through the injection tube 46. Expansion of the bladder 44 results in a force tending to push the assembly of the backing plate 22 and the hub 14a afterward of the tail shaft 16. Once the hydraulic jack mechanism of the expandable bladder 44 has loosened the hub 14a from the taper of shaft 16 the conventional hoist mechanism can be used to lift away the propeller assembly from the tail shaft.

FIG. 4

Turning now to FIG. 4, there will be described further features and modifications of a device constructed in accordance with the present invention. lllustrated is an extended flange 22c on backing plate 22 which eliminates the need for a separate withdrawal ring (as illustrated at 51 in FIG. 3). Thus, when it is desired to withdraw the hub 14a, the bolts which are located in the central part of backing plate 22 are removed and placed at the outer location where they are secured as at 52 to hub 14a.

The construction as illustrated in FIG. 4 with the extended flange 220 provides an integral assembly which eliminates the need for a separate part. This can be a great advantage in the operation of a vessel where it is difficult to store and keep on hand supplementary parts. Thus, the withdrawal procedure is extremely simple compared to certain prior art devices. The only changes in the assembly required for withdrawal are changes in location of the bolts from the central position on the backing plate 22 to the extended flange 22c.

FIG. 4 illustrates a further feature in accordance with the present invention as showing the molded corner 44a of the bladder 44. This molded corner 44a is an alternative measure to the O-ring 51 as shown in FIG. 2 for preventing the extrusion of the corner of the bladder 44.

FIG. 5

Directing attention now to FIG. 5 will be described an alternate construction which permits the fair water cap to be secured in an integral manner with the retaining plate 22. An extended flange 22d is provided which is adapted to receive a shoulder stud 60. Shoulder stud 60 is mounted in a threaded opening 60a in hub 14a. Fitted over the outstanding portion of the stud 60 is the fair water cap 20, which is secured in place by means of a nut 60b. The shoulder stud 60 can be used to restrain the retaining plate 22 during hub withdrawal and also can be used to secure the fair water cap 20. The particular design illustrated in FIG. 5 may be suited to particular applications depending upon the overall design of the fair water cap-propeller mounting assembly.

FIG. 6

In the construction illustrated in FIG. 6, the withdrawing, retaining and installing device is particularly adapted for use with a hollow tail shaft 70. For this application a backing ring 72 is shown which has many of the features described in the foregoing in connection with backing plate 22. For example, it includes the extended flange 220, the annular recess 40 and associated injection tube, the O-ring seal 43, and the piston ring 28 and associated expandable bladder 30.

A plurality of bolts are provided to secure the backing ring 72 to the hollow shaft 70, two of these bolts being shown at 80 and 82. Bolts 80 and 82 are received respectively in threaded openings 80a and 82a in the hollow shaft 70.

A withdrawal plate 86 is mounted centrally within the hollow shaft 70. Withdrawal plate 86 includes a flange 860 which rests upon a shoulder 70a of the hollow shaft 70.

In the construction illustrated in FIG. 6, the hydraulic withdrawal jack is provided by a hemispherical pressure head 90 which includes flanges 90a that are retained under a shoulder 72a of the backing ring 72. An extension 70b of the hollow tail shaft 70 provides lateral restraint for the pressure head 90 and also provides exact lateral fitting for the backing ring 72.

Mounted within the hollow space formed by the pressure head 90 and the withdrawal plate 86, is an expandable bladder 96, which performs a similar function to the bladder 44 described above. Fluid pressure is injected into the bladder 96 through an injection tube 98. A portion of the bladder 96 may extend upwardly as a sleeve around the injection tube 98 to provide a seal. When fluid pressure is injected into the bladder 96 through injection tube 98 expansion of the bladder occurs which 'results in a force pressing against the withdrawal plate 86. Hence, injection of pressure fluid into the bladder 96 results in urging of the assembly including the hub 14a aftward of the taper of the tail shaft 70.

To install a propeller and hub assembly in accordance with the device illustrated in FIG. 6, the following steps are followed:

First, the hub 14a is urged onwardly of the shaft in the usual manner. Then, the withdrawal plate 86 and the pressure head 90 are installed centrally on the hollow shaft 70. The backing ring 72 is then installed and secured onto the hollow shaft 70 by means of the bolts and 82 as described above in connectionwith the other embodiments. Fluid pressure is injected into the expandable ring 30 to cause the piston ring 28 to urge the hub 14a onto the taper of shaft 70. The hub 14a is finally retained on the shaft 70 by the tightening of the bolts 80 and 82 and the injection of sealant into the recess 40.

The procedure for withdrawal of the device illustrated in FIG. 6 is similar to that described above in connection with FIG. 4. Specifically, the bolts 80 and 82 are withdrawn from the position as illustrated and located in the bores shown for the extended flange 220. In other embodiments, of course, the device illustrated in FIG. 6 may include a separate withdrawal ring as illustrated in FIG. 3. When withdrawal is desired, fluid pressure is injected into the bladder 96 to cause expansion thereof and pressing upon the withdrawal plate 86. The hub 14a is then urged gently aftward of the shaft 70.

While the device illustrated in FIG. 6 has been described in connection with a hollow shaft 70, it can be used in other applications with a solid shaft. The large pressure head can provide the high pressures that might be required for withdrawal of a propeller and hub assembly. In such application, of course, the withdrawal plate 86 might be eliminated, and the forward edge of the bladder 96 would contact directly with the aft end of the tail shaft.

FIGS. 7 and 8 Illustrated in FIG. 7 is still another modification of the device constructed in accordance with the present invention. Several of the parts and features illustrated in FIG. 7 are the same as those described in the foregoing and their purpose and function will not be described in the following. The device illustrated in FIG. 7 provides a convenient method for starting and aligning hub 14a onto the tailshaft 16. A guide stud 100 is secured in a central axial position in the end of shaft 16. Guide stud 100 includes a threaded end 100a which is received in a corresponding threaded opening in the shaft 16 and also includes a threaded end 10Gb on which is secured a nut 102.

A hollow ram hydraulic jack is secured concentrically around the guide stud 100. The jack 104 is secured in position between the retaining plate 22 and number of spacers 106.

The backing plate 22 as illustrated in FIG. 7 is similar in construction to the plate 22 described in connection with FIG. 2 except that a central bore is provided for the mounting of the guide stud 100.

FIG. 7 shows the hub 14a in the pull-up position prior to mounting on the shaft 16 and FIG. 8 shows the hub 14a in place on the shaft 16. During installation in accordance with the device illustrated in FIGS. 7 and 8, the guide stud 100 is installed on the shaft 16 and the hub 14a placed loosely on the shaft 16 as shown in FIG.

7. The backing ring 22 is then slipped over the guide stud 100 and the hollow ram jack 104 is slipped over the end of the guide stud 100.

Next, spacers 106, if needed, are slipped over the end of the guide stud 100 and the nut 102 is threaded and tightened. The hollow ram jack 104 is then pressurized to full capacity so as to urge the backing plate 22 and the hub 14a forward on the guide stud 100 and over the tail shaft 16. The backing plate 22 and the hub 14a are then secured in position as described above by means of bolts into the shaft 16.

When the retaining plate 22 and the hub'14a are located in place on the shaft 16 as shown in FlG. 8, the guide stud 100 is removed and in its place is put a close fitting pin 110 which provides support for the expandable bladder 112. The bladder 112 is similar in construction and purpose to that described above in connection with bladder 44 in FIG. 2 except that it is shaped as a toroid with a central hole in order to permit the guide stud 100 to be secured in the tail shaft 16.

What is regarded as having been invented or discovered is:

1. A hub and shaft assembly comprising:

a shaft having a tapered outer surface;

a hub having a tapered inner surface fitting around said shaft;

a backing plate fitted on the end of said shaft, said backing plate extending over and abutting said hub;

means for securing said backing plate to said hub;

an expandable bladder mounted in a recess in said backing plate and being disposed to contact the end of said shaft; and

means for permitting the injection of fluid into said expandable bladder whereby said backing plate and hub may be withdrawn from said shaft.

2. A hub and shaft assembly as defined in claim 1 further comprising:

means for securing said backing plate to said shaft;

an annular piston mounted in an annular recess in said backing plate and being disposed to contact the surface of said hub, said piston being movable in said recess axially of said shaft;

an expandable toroidal ring mounted in a recess between said annular piston and the wall of said backing plate;

means for permitting injection of high pressure fluid into said expandable toroidal ring mounted in a recess between said annular piston and the wall of said backing plate;

means for permitting injection of high pressure fluid into said expandable toroidal ring whereby said'annular piston may be urged outwardly to force said hub onto said shaft when said means for securing said backing plate to said hub is deactivated.

3. A hub and shaft assembly as defined in claim 1 further comprising:

an annular recess in the face of said backing plate adjacent said tail shaft; a passageway extending from said annular recess through said backing plate to the rear face of said backing plate, said passageway being adapted for the injection of a sealant into said annular recess.

4. A hub and shaft assembly as defined in claim 1 further comprising:-

a central projection of said tail shaft;

a central recess formed in the face of said backing plate adjacent to said shaft, said recess being adapted to fit tightly over and mate with said central' projection such that said assembly is capable of withstanding lateral shearing forces.

5. A hub and shaft assembly as defined in claim 1 wherein said means for securing said backing plate .to said hub comprises:

over said hub beyond'the position of said annular piston;

a number of openings being formed in said extended flange at locations about the periphery thereof;

a plurality of threaded openings being formed in said hub and registering with the locations of the openings in said extended flange;

a plurality of bolts located in said openings in said hub and flange to secure said backing plate to said hub during the withdrawal operation.

6. A hub and shaft assembly as defined in claim 1 further comprising:

a withdrawal ring mounted concentrically about said backing plate and being in contact with said hub, said withdrawal ring including a flange adapted to abut a shoulder extending from said backing plate;

a number of bolts extending through bores in the periphery of said withdrawal rings, said bolts extending into threaded openings into said hub so as to secure said backing plate to said hub for the withdrawal procedure.

7. A hub and shaft assembly as defined in claim 2 wherein:

said means for securing said backing plate to said shaft comprises a number of bolts extending through bores in said backing plate and being received in threaded openings in the end of said shaft.

8. A hub and shaft assembly as defined in claim 1 further comprising:

a circular flange extending from said backing plate over said hub;

a number of bores extending through said flange about the periphery thereof, said bores registering with corresponding threaded openings in said hub, each of said bores including a counter sunk portlon;

a shoulder stud being mounted in each of said bores, the shoulder portion of each stud being adapted to fit in said counter sunk portion to secure said backing plate and hub together;

a fair water cap fitted over the end of said backing plate and over an upstanding portion of each of said shoulder studs; and

a number of nuts securing said fair water cap to said shoulder studs.

a flange extending outwardly from said backing plate ing the steps of:

9 9. The hub and shaft assembly as defined in claim 1 wherein said bladder is in the shape of a toroid having a central opening through which may be placed a central guide stud secured in said shaft.

10. A method for withdrawing a hub from a shaft 5 which is secured thereto by means of a backing plate having bolts extending through the backing plate into said shaft, comprising steps of: r

ing the steps of:

installing a withdrawal ring around the periphery of said backing plate, said withdrawal ring having one surface in engagement with said hub and a shoulder which engages with an outwardly extending flange of said backing plate; and

removing the bolts from the central position in said shaft to said withdrawal ring whereby said hub assembly, backing plate and withdrawal ring are secured in a unitary structure for withdrawal.

12. A method for installing a hub on a shaft comprisa. installing said hub loosely on said shaft;

b. locating a guide stud centrally on said shaft and projecting outwardly therefrom;

c. mounting a backing plate over said guide stud, said backing plate being dimensioned to engage with said hub;

d. locating a jack centrally around the exterior portion of said guide stud;

e. securing said jack to said guide stud;

f. actuating said jack to exert force on said backing plate so as to urge said hub forward onto said shaft.

13. A hub and shaft assembly comprising:

a hollow shaft having a tapered outer surface;

a hemispherical pressure head mounted centrally on the end of said shaft;

an expandable member located within said pressure head and being adapted to engage the end of said shaft;

a first passageway for injection of fluid into said expandable bladder;

a backing ring surrounding said pressure head and being secured to said shaft, said backing ring extending over said hub and being adapted to engage the surface of said hub; I

an annular piston formed in an annular recess of said backing ring and being adapted to move axially of said shaft engagement with said hub;

an expandable ring located in a recess between said loading ring and said backing plate;

a second passageway adapted to inject fluid into said expandable ring, such that-fluid pressure may be injected through said second passageway into said expandable ring to force said loading ring outwardly into engagement with said hub, thus urging 65 said hub onward of said shaft.

14. A hub and shaft assembly as defined in claim 13 further comprising:

an annular recess formed in said backing ring on the surface adjacent to said shaft, said annular recessbeing in communication with said bolts;

a third passageway for injecting sealant into said annular recess so as to seal said backing plate to said shaft.

15. A hub and shaft assembly as defined in claim 13 further comprising:

an extended flange of said backing ring extending beyond the position of said annular piston, said extended flange including anumber of bores which register with corresponding threaded openings in said hub, whereby during withdrawal of said hub from said shaft, bolts may be secured through said bores and received in said threaded openings, to

secure said backing ring to said hub.

16. A hub and shaft assembly comprising:

a shaft having a tapered outer surface;

a hub having a tapered outer surface extending around said shaft;

a backing plate located at the end of said shaft, said backing plate extending over and abutting said hub;

a guide stud mounted centrally through a bore of said backing plate and fixed axially in said shaft;

a jack secured around said guide stud and being adapted to exert pressure on the outward face of said backing plate;

means for securing said jack in fixed position with respect to said guide stud, whereby said jack may be actuated to urge said backing plate and hub assembly onward of said shaft.

17. A device for installing, retaining and withdrawing a hub on a shaft, comprising:

a backing plate having a front and rear surface, said backing plate being adapted to engage the outward end of a shaft and extend over and engage a hub located around a shaft;

means for securing said backing plate to the end of a shaft;

an annular piston formed in a first annular recess in the front face of said backing plate, said annular piston being adapted to move in said recess axially of a shaft;

means for securing said backing plate to the hub;

an expandable ring member located in an annular recess between said annular piston and said backing plate;

a first passageway extending between said expanda ble ring member and an exterior portionof said backing such that fluid pressure may be injected into said expandable ring to urge said annular piston outward when said backing plate is secured to the shaft and not to the hub, thereby exerting force to urge a hub onto a shaft;

a central recess formed on the front face of said backing plate, said recess being adapted to engage and mate with a central projection of a shaft so as to provide a strong connection to withstand lateral shearing forces;

an expandable member located in a second recess formed on the front face of said backing plate, said expandable member being adapted to engage the end of a shaft; and

a second passageway extending from said expanda ble member to the exterior of said backing plate whereby fluid may be injected under pressure into said expandable member to exert force on the end of said shaft when said backing plate is secured to the hub and not to the shaft, thereby removing the hub from the shaft. 18. A device as defined in claim 17 further comprising:

means for preventing extrusion of said expandable member into the interface between the wall of the l recess of said backing plate and said central projection.

l9. A device as defined in claim 18 wherein said means for preventing extrusion comprises:

an O-ring mounted about the wall of said recess and adapted to engage the end of said central projectlon.

20. A device as defined in claim 17 wherein said expandable member is in the shape of an oblate spheroid.

21. A device as defined in claim 17 wherein said expandable member is in the shape of a toroid.

22. A device as defined in claim 17 wherein said means for securing said backing plate to a shaft comprises a number of bolts extending through bores in said backing plate.

23. A device as defined in claim 19, further comprisa second annular recess formed on the front side of said backing plate, said second annular recess being open to the end of a shaft, said second annular recess being in fluid communication with said bores for bolts;

a third passageway extending from said annular recess to the exterior of said backing plate such that sealant may be injected under pressure through said passageway into said second annular recess.

24. A device as defined in claim 23 further comprismg:

an O-ring seal mounted in a third annular recess in the front side of said backing plate and being adapted to engage the surface of said hub thereby forming a seal for sealant injected into said second annular recess.

25. A device as defined in claim 17 further comprisan extended flange of said backing plate adapted to engage said hub beyond the location of said annular piston;

a number of bores located concentrically about the center of said backing plate on said extended flange whereby bolts may be located in said bores to secure said backing plate to said hub for withdrawal.

26. A device as defined in claim 25 wherein:

said extended flange is a separate piece from said backing plate adapted for removal except during withdrawal procedure, said separate piece comprising:

a shoulder adapted to engage a flange portion of the periphery of said backing ring.

27. In a mounting assembly for a massive ships propeller having a hub with a tapered bore which is fitted onto a tailshaft having a tapered end portion and end face, the improvement comprising:

a backing plate having an inner face which is positioned closely adjacent the end face of the tailshaft and having a surrounding portion overlapping at least a portion of the hub;

means for removably securing the hub-overlapping portion of the backing plate to the hub; and

fluid-pressure operated means located in the inner face of the backing plate and positioned to act on the end face of the tapered end of the tailshaft to force the massive propeller to withdraw from the tapered end of the tailshaft,'when subjected to the action of fluid under pressure.

28. A mounting assembly according to claim 27 in which the inner face of the backing plate has a circular recessed portion of smaller inner diameter than the maximum outside diameter of the end portion of the tailshaft, and in which a projection of the end portion of the tailshaft is accommodated.

29. A mounting assembly according to claim 27 in which the end portion of the tailshaft is of solid material. I

30. A mounting assembly according to claim 27 in which the end portion of the tailshaft has a hollow bore and in which a plate member having a flat side facing aft is mounted in a recess formed in the bore of the end portion of the tailshaft, the flat side providing a surface against which the fluid-operated means can act.

31. A mounting assembly according to claim 27 further comprising:

means for removably securing the backing plate to the end portion of the tailshaft;

fluid pressure operated means, different from the first mentioned one, located in the hub overlapping portion of the hub and positioned to act on the hub to force the massive propeller into position on the tailshaft.

32. A mounting assembly according to claim 27 in which:

the hub has an end face in which there are a number of tapped holes;

the overlapping portion of the backing plate has a number of bolt holes aligned with the tapped holes in the hub; and

bolts extend removably through the bolt holes and into the tapped holes to removably secure the backing plate to the hub.

33. A mounting assembly according to claim 27 in which:

the end face of the tailshaft has a number of tapped holes;

the backing plate has a number of bolt holes aligned with the tapped holes; and,

bolts extending through the bolt holes and into the tapped holes in the tailshaft to removably secure the backing plate to the tailshaft.

34. A mounting assembly according to claim 33 in which the backing plate, hub, tailshaft and bolts are constructed and arranged such that the same bolts can be used to secure the backing plate removably either to the tailshaft for installation of the propeller or to the hub for withdrawal of the propeller.

35. In a mounting assembly for a massive ships propeller having a hub with a tapered bore which is fitted onto a tailshaft having a tapered end portion and end face, including:

a backing plate having an outer face and an inner face which is positioned closely adjacent the end face of the tailshaft and having a surrounding portion overlapping at least a portion of the hub, means for removably securing the backing plate to the end portion of the shaft, fluid-pressure operated means located in the hub overlapping portion of the backing plate and positioned to act on the hub tail to force the massive propeller on the tapered end of the tailshaft, when subjected to the action of fluid under pressure, the improvement by which the inner face of the backing plate has an annular recess and a passageway extending from the annular recess to the outer face of the backing plate, whereby sealant may be injected through the passageway to create a water-tight seal between the backing plate and the end face of the tailshaft.

36. In the mounting assembly according to claim 35 in which the end face of the tailshaft has tapped holes arranged in a circular pattern, the backing plate has bolt holes and bolts extend removably through the bolt holes, the improvement in which the annular recess in the backing plate extends through and surrounds the bolt holes to create a seal impervious to water through the bolt holes when the bolts are in place.

37. A method of operating the mounting assembly according to claim 27 to remove the propeller from the tailshaft, comprising the steps of:

removing the bolts securing the backing plate to the tailshaft and installing them in the bolt holes in the hub overlapping portion and extending into the tapped holes in the hub to secure the backing plate to the hub; and,

injecting fluid pressure into the fluid-operated means located in the inner face of the backing plate, thereby causing said fluid-operated means to act on the end face of the tailshaft to urge the hub aftward.

* l IR 

1. A hub and shaft assembly comprising: a shaft having a tapered outer surface; a hub having a tapered inner surface fitting around said shaft; a backing plate fitted on the end of said shaft, said backing plate extending over and abutting said hub; means for securing said backing plate to said hub; an expandable bladder mounted in a recess in said backing plate and being disposed to contact the end of said shaft; and means for permitting the injection of fluid into said expandable bladder whereby said backing plate and hub may be withdrawn from said shaft.
 2. A hub and shaft assembly as defined in claim 1 further comprising: means for securing said backing plate to said shaft; an annular piston mounted in an annular recess in said backing plate and being disposed to contact the surface of said hub, said piston being movable in said recess axially of said shaft; an expandable toroidal ring mounted in a recess between said annular piston and the wall of said backing plate; means for permitting injection of high pressure fluid into said expandable toroidal ring mounted in a recess between said annular piston and the wall of said backing plate; means for permitting injection of high pressUre fluid into said expandable toroidal ring whereby said annular piston may be urged outwardly to force said hub onto said shaft when said means for securing said backing plate to said hub is deactivated.
 3. A hub and shaft assembly as defined in claim 1 further comprising: an annular recess in the face of said backing plate adjacent said tail shaft; a passageway extending from said annular recess through said backing plate to the rear face of said backing plate, said passageway being adapted for the injection of a sealant into said annular recess.
 4. A hub and shaft assembly as defined in claim 1 further comprising: a central projection of said tail shaft; a central recess formed in the face of said backing plate adjacent to said shaft, said recess being adapted to fit tightly over and mate with said central projection such that said assembly is capable of withstanding lateral shearing forces.
 5. A hub and shaft assembly as defined in claim 1 wherein said means for securing said backing plate to said hub comprises: a flange extending outwardly from said backing plate over said hub beyond the position of said annular piston; a number of openings being formed in said extended flange at locations about the periphery thereof; a plurality of threaded openings being formed in said hub and registering with the locations of the openings in said extended flange; a plurality of bolts located in said openings in said hub and flange to secure said backing plate to said hub during the withdrawal operation.
 6. A hub and shaft assembly as defined in claim 1 further comprising: a withdrawal ring mounted concentrically about said backing plate and being in contact with said hub, said withdrawal ring including a flange adapted to abut a shoulder extending from said backing plate; a number of bolts extending through bores in the periphery of said withdrawal rings, said bolts extending into threaded openings into said hub so as to secure said backing plate to said hub for the withdrawal procedure.
 7. A hub and shaft assembly as defined in claim 2 wherein: said means for securing said backing plate to said shaft comprises a number of bolts extending through bores in said backing plate and being received in threaded openings in the end of said shaft.
 8. A hub and shaft assembly as defined in claim 1 further comprising: a circular flange extending from said backing plate over said hub; a number of bores extending through said flange about the periphery thereof, said bores registering with corresponding threaded openings in said hub, each of said bores including a counter sunk portion; a shoulder stud being mounted in each of said bores, the shoulder portion of each stud being adapted to fit in said counter sunk portion to secure said backing plate and hub together; a fair water cap fitted over the end of said backing plate and over an upstanding portion of each of said shoulder studs; and a number of nuts securing said fair water cap to said shoulder studs.
 9. The hub and shaft assembly as defined in claim 1 wherein said bladder is in the shape of a toroid having a central opening through which may be placed a central guide stud secured in said shaft.
 10. A method for withdrawing a hub from a shaft which is secured thereto by means of a backing plate having bolts extending through the backing plate into said shaft, comprising steps of: a. removing said bolts from the position in said shaft and locating them to secure a flange of said backing plate to said hub without reversing said backing plate; and b. injecting fluid pressure into a hydraulic jack located in said backing plate, said hydraulic jack thereby exerting pressure on the end of said shaft, whereby said hub and backing plate assembly is urged outwardly of said shaft.
 11. A method as defined in claim 10 further comprising the steps of: installing a withdrawal ring around the periphery of said backing plate, saId withdrawal ring having one surface in engagement with said hub and a shoulder which engages with an outwardly extending flange of said backing plate; and removing the bolts from the central position in said shaft to said withdrawal ring whereby said hub assembly, backing plate and withdrawal ring are secured in a unitary structure for withdrawal.
 12. A method for installing a hub on a shaft comprising the steps of: a. installing said hub loosely on said shaft; b. locating a guide stud centrally on said shaft and projecting outwardly therefrom; c. mounting a backing plate over said guide stud, said backing plate being dimensioned to engage with said hub; d. locating a jack centrally around the exterior portion of said guide stud; e. securing said jack to said guide stud; f. actuating said jack to exert force on said backing plate so as to urge said hub forward onto said shaft.
 13. A hub and shaft assembly comprising: a hollow shaft having a tapered outer surface; a hemispherical pressure head mounted centrally on the end of said shaft; an expandable member located within said pressure head and being adapted to engage the end of said shaft; a first passageway for injection of fluid into said expandable bladder; a backing ring surrounding said pressure head and being secured to said shaft, said backing ring extending over said hub and being adapted to engage the surface of said hub; an annular piston formed in an annular recess of said backing ring and being adapted to move axially of said shaft engagement with said hub; an expandable ring located in a recess between said loading ring and said backing plate; a second passageway adapted to inject fluid into said expandable ring, such that fluid pressure may be injected through said second passageway into said expandable ring to force said loading ring outwardly into engagement with said hub, thus urging said hub onward of said shaft.
 14. A hub and shaft assembly as defined in claim 13 further comprising: an annular recess formed in said backing ring on the surface adjacent to said shaft, said annular recess being in communication with said bolts; a third passageway for injecting sealant into said annular recess so as to seal said backing plate to said shaft.
 15. A hub and shaft assembly as defined in claim 13 further comprising: an extended flange of said backing ring extending beyond the position of said annular piston, said extended flange including a number of bores which register with corresponding threaded openings in said hub, whereby during withdrawal of said hub from said shaft, bolts may be secured through said bores and received in said threaded openings, to secure said backing ring to said hub.
 16. A hub and shaft assembly comprising: a shaft having a tapered outer surface; a hub having a tapered outer surface extending around said shaft; a backing plate located at the end of said shaft, said backing plate extending over and abutting said hub; a guide stud mounted centrally through a bore of said backing plate and fixed axially in said shaft; a jack secured around said guide stud and being adapted to exert pressure on the outward face of said backing plate; means for securing said jack in fixed position with respect to said guide stud, whereby said jack may be actuated to urge said backing plate and hub assembly onward of said shaft.
 17. A device for installing, retaining and withdrawing a hub on a shaft, comprising: a backing plate having a front and rear surface, said backing plate being adapted to engage the outward end of a shaft and extend over and engage a hub located around a shaft; means for securing said backing plate to the end of a shaft; an annular piston formed in a first annular recess in the front face of said backing plate, said annular piston being adapted to move in said recess axially of a shaft; means for securing said backing plate to the hub; an expandable ring member located in an annular recess between said annular piston and said backing plate; a first passageway extending between said expandable ring member and an exterior portion of said backing such that fluid pressure may be injected into said expandable ring to urge said annular piston outward when said backing plate is secured to the shaft and not to the hub, thereby exerting force to urge a hub onto a shaft; a central recess formed on the front face of said backing plate, said recess being adapted to engage and mate with a central projection of a shaft so as to provide a strong connection to withstand lateral shearing forces; an expandable member located in a second recess formed on the front face of said backing plate, said expandable member being adapted to engage the end of a shaft; and a second passageway extending from said expandable member to the exterior of said backing plate whereby fluid may be injected under pressure into said expandable member to exert force on the end of said shaft when said backing plate is secured to the hub and not to the shaft, thereby removing the hub from the shaft.
 18. A device as defined in claim 17 further comprising: means for preventing extrusion of said expandable member into the interface between the wall of the recess of said backing plate and said central projection.
 19. A device as defined in claim 18 wherein said means for preventing extrusion comprises: an O-ring mounted about the wall of said recess and adapted to engage the end of said central projection.
 20. A device as defined in claim 17 wherein said expandable member is in the shape of an oblate spheroid.
 21. A device as defined in claim 17 wherein said expandable member is in the shape of a toroid.
 22. A device as defined in claim 17 wherein said means for securing said backing plate to a shaft comprises a number of bolts extending through bores in said backing plate.
 23. A device as defined in claim 19, further comprising: a second annular recess formed on the front side of said backing plate, said second annular recess being open to the end of a shaft, said second annular recess being in fluid communication with said bores for bolts; a third passageway extending from said annular recess to the exterior of said backing plate such that sealant may be injected under pressure through said passageway into said second annular recess.
 24. A device as defined in claim 23 further comprising: an O-ring seal mounted in a third annular recess in the front side of said backing plate and being adapted to engage the surface of said hub thereby forming a seal for sealant injected into said second annular recess.
 25. A device as defined in claim 17 further comprising: an extended flange of said backing plate adapted to engage said hub beyond the location of said annular piston; a number of bores located concentrically about the center of said backing plate on said extended flange whereby bolts may be located in said bores to secure said backing plate to said hub for withdrawal.
 26. A device as defined in claim 25 wherein: said extended flange is a separate piece from said backing plate adapted for removal except during withdrawal procedure, said separate piece comprising: a shoulder adapted to engage a flange portion of the periphery of said backing ring.
 27. In a mounting assembly for a massive ship''s propeller having a hub with a tapered bore which is fitted onto a tailshaft having a tapered end portion and end face, the improvement comprising: a backing plate having an inner face which is positioned closely adjacent the end face of the tailshaft and having a surrounding portion overlapping at least a portion of the hub; means for removably securing the hub-overlapping portion of the backing plate to the hub; and fluid-pressure operated means located in the inner face of the backing plate and positioned to act on the End face of the tapered end of the tailshaft to force the massive propeller to withdraw from the tapered end of the tailshaft, when subjected to the action of fluid under pressure.
 28. A mounting assembly according to claim 27 in which the inner face of the backing plate has a circular recessed portion of smaller inner diameter than the maximum outside diameter of the end portion of the tailshaft, and in which a projection of the end portion of the tailshaft is accommodated.
 29. A mounting assembly according to claim 27 in which the end portion of the tailshaft is of solid material.
 30. A mounting assembly according to claim 27 in which the end portion of the tailshaft has a hollow bore and in which a plate member having a flat side facing aft is mounted in a recess formed in the bore of the end portion of the tailshaft, the flat side providing a surface against which the fluid-operated means can act.
 31. A mounting assembly according to claim 27 further comprising: means for removably securing the backing plate to the end portion of the tailshaft; fluid pressure operated means, different from the first mentioned one, located in the hub overlapping portion of the hub and positioned to act on the hub to force the massive propeller into position on the tailshaft.
 32. A mounting assembly according to claim 27 in which: the hub has an end face in which there are a number of tapped holes; the overlapping portion of the backing plate has a number of bolt holes aligned with the tapped holes in the hub; and bolts extend removably through the bolt holes and into the tapped holes to removably secure the backing plate to the hub.
 33. A mounting assembly according to claim 27 in which: the end face of the tailshaft has a number of tapped holes; the backing plate has a number of bolt holes aligned with the tapped holes; and, bolts extending through the bolt holes and into the tapped holes in the tailshaft to removably secure the backing plate to the tailshaft.
 34. A mounting assembly according to claim 33 in which the backing plate, hub, tailshaft and bolts are constructed and arranged such that the same bolts can be used to secure the backing plate removably either to the tailshaft for installation of the propeller or to the hub for withdrawal of the propeller.
 35. In a mounting assembly for a massive ship''s propeller having a hub with a tapered bore which is fitted onto a tailshaft having a tapered end portion and end face, including: a backing plate having an outer face and an inner face which is positioned closely adjacent the end face of the tailshaft and having a surrounding portion overlapping at least a portion of the hub, means for removably securing the backing plate to the end portion of the shaft, fluid-pressure operated means located in the hub overlapping portion of the backing plate and positioned to act on the hub tail to force the massive propeller on the tapered end of the tailshaft, when subjected to the action of fluid under pressure, the improvement by which the inner face of the backing plate has an annular recess and a passageway extending from the annular recess to the outer face of the backing plate, whereby sealant may be injected through the passageway to create a water-tight seal between the backing plate and the end face of the tailshaft.
 36. In the mounting assembly according to claim 35 in which the end face of the tailshaft has tapped holes arranged in a circular pattern, the backing plate has bolt holes and bolts extend removably through the bolt holes, the improvement in which the annular recess in the backing plate extends through and surrounds the bolt holes to create a seal impervious to water through the bolt holes when the bolts are in place.
 37. A method of operating the mounting assembly according to claim 27 to remove the propeller from the tailshaft, comprising the steps of: removing the bolts securing the backing plate to the tailshaft and installinG them in the bolt holes in the hub overlapping portion and extending into the tapped holes in the hub to secure the backing plate to the hub; and, injecting fluid pressure into the fluid-operated means located in the inner face of the backing plate, thereby causing said fluid-operated means to act on the end face of the tailshaft to urge the hub aftward. 